Method of and means for coating inner surfaces of hollow bodies



I 1, 21, March 15, 1927. R. P. JACKSON 6 016;

METHOD OF AND MEANS FOR COATING INNER SURFACES OF HOLLOW BODIES Filed June 4, 1923 v INVENTOR WT SSES: 9K3. Ray flJaa/rsa Z V I ATTORNEY UNITED sTT s my 1. .mcxson, or EDGEWOODVPARK, PENNSYLVANIA, assrenon r wns'rmenousn ELEGIBIC & MANUFACTURING comm, a comomrron or rmmsnvnma.

moi) or m mus r012. conrnve Application filed lune 4,

- 'My invention relates to a method of, and means for coating the inner surfaces of hollow bodies and particularly to providing a perimetral band of .coating material on 5 the inner surface of a recessed insulator adjacent to the mouth of the recess. One object of my invention isto provide a method and means of the above indicated character that shall facilitate and economize the manufacture of hollow bodies, such as insulators of the plural-part nested typein which it is'desired to coat the inner surfaces thereof in a certain manner.

Another object of my invention is to pro 18 vide a method of, and means for, applying a uniform coating of material to the nner surface of a body adjacent to the entrance of the body.

While my invention may be employed in M connection with hollow of var ous characters, sizes and materials, an immediate application thereof is in connection with an insulating member having recesses for the reception of a similar insulating member to which it is to be attached.

The formerly employed methods of coating the inner surfaces of hollow bodles by dipping and by applying coating material with a brush are inadequate for the purfor which my invention is intended.

or example, in dipping a hollow body to coat its inner surface, the outer surface will be coated also and in applyinga brush, the material must be such as will readily. lend itself to application thereby. Further, in employing a brush, the hollow body must be large enou h to admit the same, and, sometimes, the and of the operator.

To apply the coating material to an exact 40 limiting line on the inside surface only of. a

hollow body,'is not possible by dipping, because, as pointed out above, the outside of the body bghcoated also, and mtemi loymg' a r e opera 'on is imprac ica r requires great skill, depending upon the I size of the opening. The so-called air brush is also subject to limitations which render it insuflicient for my purposes.

Assume a hollow body which it is desired to coat, on its inside surface only, to an exact inner perimetral line some distance from the mouth of the hollow body. One of INNER srmracns or HOLLOW Bonnie.

1923. Serial Ho. 648,143. v

the members of a plural-part insulator of" the nestedtype'is such a body. In connectng the nested portions of an insulator, it is usualto'employ a cementthat' is sub 'ected to deterioration by moisture. To seal the exposed edges of the cement, it is desirable to employ a gum inthe form of perimetral bands that are placed on the respective parts before the steaming operation, whichcauses the bands to come together in a homogeneous mass. This construction is fully shown and described in a copending pp ication .ofN. A. lVahlberg, Serial No. 633,721 filed April 21, 1923, for insulators, and assigned to the Westinghouse Electric & Manufacturing Company. Y

One of the members has a portion of inverted substantially cup-shape having a uniform band of gummy material on its inner surface adjacent to its mouth. This material does not lend itself to ready application with a brush.

In practicing my invention, I provide meansfor causing a coating liquid to enter a hollow body in volume'or bulk. The liquid is controlled to enter the body to a predetermined exact position or inner perimetal line and to be withdrawn from the body to provide a uniform band of coating material on the inner surface of the body.

Figure 1, of the accompanying drawings,

is. a. side view, partially in elevation and partially in section of a device for effecting the method of my invention, showing thev parts in the position assumed before the coating operation, and

- 'Fig. 2 is a view similar to Fig. 1, showing the coating liquid raised to its inner limiting position in the hollow body.

In ()general, a device for practicing the meth of my invention may comprise, a receptacle or tank 1 for containing a body ofcoating liquid 2, a lid member 3 for the receptacle 1 and which constitutes a sup- 7 more, members 4. The member 4, in this instance being a unit of a plural-part insulator, is provided with a petticoat portlon 7 I which is adapted to rest on the member 3.

A depending portion 8, of inverted substantially cupshape and having a recess 9, gxtends through an opening 14 in the memer 3.

Ordinarily, the level of the liquid 2"is so adjusted that thesurface of the liquid barely touches the mouth\of the recess 9. However, the lower edge of the portion 8 may be immersed in the liquid 2, depending on how far above the lower end of the member 4 it is desired to have the liquid engage the outer surface thereof. v

The tubular member 5 is supported in a side Wall of the-receptacle 1, as by a bushing 10, andis connected, through the valve 6, to a vacuum pump having constant operating conditions. The valve 6 is preferably of the two-way type having a passage 11 therem for connecting the recess 9 to the source of vacuum and a passage 12 for connecting the recess 9 to the atmosphere.

In operation, the vacuum pump is adjusted to a valve which, when the valve 6 is in the position shown in Fig. 2, will cause the liquid to rise to a predetermined level. Initially, and as shown in Fig. 1, the member 4 is placed through the opening 4 in the member 3 to the position shown, in which position, the lower end of the member 4 is in engagement with the surface of the liquid 2. With the valve 6 in the position shown in Fig; 1, the recess 9 communicates directly with the atmosphere and the level of the liquid 2 in the recess is thereby unaffected.

By turning the valve 6 to the position shown in Fig. 2, the vacuum pump is connected to the recess 9 in which the liquid rises to the level shown. To avoid disturbing the liquid level such as would occur if the member 4 were to be lifted away from the member 3 while the level of the liquid were as shown in Fig. 2, the valve 6 is turned back to the position shown in Fig. 1. This action admits air pressure to the recess 9 and causes the level of the liquid to recede gradually, thus leaving a smooth perimetral and of coating material around the inner 7 surface of the member 4 adjacent to the month of the recess 9.

Various modifications of my invention, such as havlng the tubular member 5 communicate only with the atmosphere and in protecting the outer surface of the portion 8, while the liquid is caused to enter the recess, will be apparent,-and I desire that all such modifications be .included in the scope of my invention, as set forth in the appended claims.

I claim as my invention:

1. A device for coating the inner surface of a recessed member comprising a receptacle for a coating liquid over which the .member is placed with an entrance to said said vacuum producing -means and to the atmosphere.

3. The combination with an insulator having a recess of substantially cup-shape, of means for applying a coating liquid in the form of a perimetral band on the inner sur-.

face of the cup, adjacent to its mouth, comprising a .receptacle for the coating liquid, means for supporting the insulator with the cup inverted and the mouth of the cup engaging the surface of the liquid, a tubular member connected between the interior of the cup and avacuum producing means adjusted to a constant value in accordance with the desired width of said coating band, and

means for controlling the rise and fall of the liquid in the cup.

4. A device for coating the inner surface of a recessed member comprising a receptacle for a coating liquid over which the member is placed with an entrance to said recess adjacent to the surface .of the liquid and means including a tubular member extending between the exterior and the interior of the recess for controlling the liquid level in the recess by fluid pressure.

'5. A device for coating the inner surface of an insulator having a-recess of substantially cup-shape, and a petticoat intermediate its ends, comprising a receptacle for a coating liquid, means engaging said petticoat for supporting the insulator with. the cup inverted and the mouth thereof sealed by the coating liquid, and means including a tubular member extending between the interior and the exterior of the cup for causing the liquid to rise and fall,in the cup by fluid-pressure changes in the cup.

6. A device-for coating the inner surface- 1,021,010 I a i a liquid to rise and fall in the cup by fluidthe liquid seals said mouth and in withdrawpressure changes in the cup. ing air from the cup. I

7. The method of coating the interior sur- In testimony whereof, I have hereunto 10 face only of a member of substantially cup subscribed my name this 24th day of May, 6 shape having imperforate walls, compr' 1923.

placing the mouth of the cup in invert I position over a body of coating liquid so that RAY P. JACKSON. 

